Brexit officials for both the U.K. and the EU have claimed some progress in the latest round of talks – somewhat a change in tone, but only a small step in the right direction given the amount of work that lies ahead.

David Davis, the U.K.'s Brexit secretary, told reporters Thursday that negotiators had achieved "decisive steps forward" during the fourth round of talks, including on citizens' rights. EU's chief negotiator Michel Barnier nodded in agreement, but added that they aren't yet in a position that allows the discussion of future trade arrangements – set to happen after October.

Another stumbling block is the exit bill that the U.K. has to pay. So far, the negotiations have not included this point.

"Until now, we have no paper from the United Kingdom about financial commitments that you can negotiate, we do not know a final figure," Elmar Brok, a member of the European Parliament told CNBC Friday.

According to Barnier, the talks could drag on for months if there is no agreement on how much the U.K. will have to pay before it leaves the EU. However, Barnier took two positive things from the speech that U.K. Prime Minister Theresa May gave last week in Italy.

"May said two things," Barnier told reporters Thursday — that no member state should pay more or receive less because of Brexit and that the U.K. will honor its commitments, he said.

Speaking to reporters Friday morning in Estonia, May welcomed the progress made. She added that she wants EU citizens living in the U.K. to remain, but she's also looking for guarantees for British citizens living in EU nations.

Stefan Rousseau | PA Images | Getty Image

Brexit Secretary David Davis arriving in Downing Street, London, for a Cabinet meeting.

In Brussels, however, officials have complained that it's taking too long for the U.K. government to come forward.

"I have the feeling we never know who to talk (to)," Brok told CNBC, saying that the vote for Brexit was made in summer 2016, while the triggering of the legal process to leave the EU only came in March. The U.K. had a snap election in June and there's a Conservative Party conference on the way that could see a leadership challenge.

Andrew Hood, former negotiator at the U.K. representation to the EU, told CNBC: "The progress of talks is slow and there are clearly some big stumbling blocks, in particular around the jurisdiction of the European Court of Justice."

European leaders are expected to discuss the ongoing Brexit negotiations at a summit next month. According to Hood: "Leaders are only likely to note the progress made, stress the need for more progress and say very little else."

To escape the current level of uncertainty, tens of thousands more British citizens have asked for citizenship in other EU counties, the BBC reported Friday.

Between July 2016 and June 2017, the number of applications more than doubled from the previous year. Ireland has so far received the highest number of applications.